greybus: raw: fix use-after-free if write is called after disconnect
Affects Linux kernel versions from 4.9.0 where a user writes to the greybus raw chardev after disconnect. Fixed in 6.6.160, 6.12.114 and 7.0.10. No vendor severity rating is given; CVSS is 7.8 (high).
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 6.6.160, 6.12.114, 7.0.10
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: greybus: raw: fix use-after-free if write is called after disconnect If a user writes to the chardev after disconnect has been called, the kernel panics with the following trace (with CONFIG_INIT_ON_FREE_DEFAULT_ON=y): BUG: kernel NULL pointer dereference, address: 0000000000000218 ... Call Trace: <TASK> gb_operation_create_common+0x61/0x180 gb_operation_create_flags+0x28/0xa0 gb_operation_sync_timeout+0x6f/0x100 raw_write+0x7b/0xc7 [gb_raw] vfs_write+0xcf/0x420 ? task_mm_cid_work+0x136/0x220 ksys_write+0x63/0xe0 do_syscall_64+0xa4/0x290 entry_SYSCALL_64_after_hwframe+0x77/0x7f Disconnect calls gb_connection_destroy, which ends up freeing the connection object. When gb_operation_sync is called in the write file operations, its gets a freed connection as parameter and the kernel panics. The gb_connection_destroy cannot be moved out of the disconnect function, as the Greybus subsystem expect all connections belonging to a bundle to be destroyed when disconnect returns. To prevent this bug, use a rw lock to synchronize access between write and disconnect. This guarantees that the write function doesn't try to use a disconnected connection.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
4.9
- KernelLinux
From 4.9.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.114; From 6.13.0 · fixed in 7.0.10
References 5
Questions about CVE-2026-53024
What does this mean?
Writing to the greybus raw character device after it has been disconnected uses a connection object that has already been freed. This causes a NULL pointer dereference and a kernel panic.Source: git.kernel.org
Am I affected, and how do I check?
Linux kernel 4.9.0 up to 6.6.160, 6.7.0 up to 6.12.114, and 6.13.0 up to 7.0.10 are listed as affected. Check the running version with uname -r and compare it against these ranges.Source: git.kernel.org
What should I do about it?
Update to the fixed kernel for the release line in use: 6.6.160, 6.12.114, or 7.0.10 or later.Source: git.kernel.org
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data